There are 100 students in a blind school. mr. and mrs. ramesh wished to serve them milk. they served the milk in a hemispherical bowl with daimeter 21cm made up of ecofreindly material to each student.(a) how many litres of milk was served by them to all 100 students.(b) what was the total cost of milk if the rate of the milk was rs.10 per litre ? (c) write the value shown by them.

A) The radius of the hemisphere is:
r = d÷2 = 21÷2 = 10.5cm

We can now calculate the volume of a hemisphere:
V = 2/3 π r³
   =  2/3 π (10.5)³
   = 2423 cm³

As we can consider that 1000cm³ contains 1l, each bowl contains 
2423 ÷ 1000 =2.423l.
In total, the milk served will be: 2.423 × 100 = 242l

B) The total cost will be: 
242 × 10 = 2420Rs

C) Mr.and Mrs. Ramesh helped blind students using an eco-friendly material, therefore they have shown social and environmental values.